(i) Field of the Invention
The present invention relates to a device for injecting a refrigerant into a product mixer.
Such a mixer, also known as a "churn," equipped with a device for injecting a refrigerant, for example nitrogen, is used especially in the field of the agri-foodstuffs industry for separately deep-freezing each ingredient of ready-cooked dishes or for coating with sauce and simultaneously deep-freezing deep-frozen products.
(ii) Description of Related Art
In the related art, a device for injecting refrigerant into a product mixer generally comprises a pipe for injecting the refrigerant equipped with an injection nozzle intended to be connected to the mixer and with at least one region of reduced cross section suitable for creating an expansion in the fluid. In this type of device, the region of reduced cross section consists of a calibrated orifice positioned at the end of the injection nozzle, at the inlet of the vessel of the mixer. The refrigerant, conventionally consisting of liquid nitrogen, is then injected, via the region of reduced cross section, into the vessel by means of the injection nozzle.
This construction makes it possible to create an expansion in the refrigerant at the inlet of the churn. However, it has a number of drawbacks, especially because of the fact that the calibrated orifice made in the injection nozzle causes a relatively large dispersion of the flow, which adopts a cone shape. It therefore does not allow a stream of liquid nitrogen to be obtained which penetrates deeply into the churn.